Bast fabrics have gained more and more popularity with people, as they are low electrostatic material, and provide antibacterial properties and great absorbency. However, bast fibre, especially jute fibres, include a great amount of lignin, which is more rigid and brittle than cotton fibres. Generally, bast fibres need to be humidified for health preserving before the fibres are spun by existing technology, wherein, health preserving refers to putting bast fibres in a certain temperature and humidity environment for a certain period of time. Health preserving can improve the flexibility of bast fibres. However, because of the loss of water during processing, bast fibres will become dry and easily broken. For instance, in the art of blended spinning bast fibres and other fibres, when the yarn is 12s in thinness, the end breakage rate may reach up to 300-400 times per hour for each machine on average, which greatly raises the difficulty of bast fibres spinning, thereby reducing work efficiency and the quality of products.